– Logic

There are two types of logic, formal logic and informal logic. In this article, we will look at formal logic in more detail, so there are many types of formal logic, but among them there are three most important types that cover the rest to a great extent, they are;

1) Deductive logic

2) Inductive Logic

3) Abductive Logic

1) Deductive logic

In deductive reasoning we always derive something new from something we already know. Deductive reasoning (if done correctly) is guaranteed to be 100% correct. 

– Types of deductive logic

(Tips of Inductive Logic)

1) Categorical syllogism

Argument in deductive logic is also done in a way that we call categorical syllogism. It has a Major Premise which is a statement that holds for everything. That is, there is a general statement and a minor premise that is only about something specific. And there is a middle term that connects the two but is not present in the result. An example of deductive logic reasoning would be something like this:

• All mammals are warm blooded. 

• A whale is a mammal. 

so,

• Whale blood is also warm. 

Here, as can be seen, we knew two things that all mammals are warm-blooded and that whales are mammals, so we deduced that whales are also warm-blooded. All is for mammals while from this we learned about whales. 

• It has the major premise "All mammals are warm-blooded." Is,

• The minor premise “a whale is a mammal”, and

• Meanwhile, the middle term that connects the two premises is "mammals" from which we are deriving that whales are warm-blooded. 

2) Hypothetical syllogism

There are also types of deductive logic such as hypothetical syllogism. An example of this reasoning would be:

• I will get good marks in exams only if I go to school. 

• Only if I score good marks in exams will I become a successful person. 

so,

• I will become a successful person only if I go to school. 

Generally speaking, if A = B and B = C, then A = C. 

3) Disjunctive syllogism

It is a deductive reasoning in which we work with a statement that states two things that are contradictory to each other ie either this will happen or that will happen then we draw a conclusion based on the information given in the second premise. are

For example:

• Either it will rain or the sun will come out. 

• The sun did not rise. 

so,

• it is raining. 

4) Modus ponens

This is deductive reasoning in which we work with a statement in which the occurrence of one thing or event necessitates the occurrence of another. 

such as:

• If it rains, the ground will become wet. 

• it is raining. 

so,

• The ground is wet. 

As can be seen, if the first part is proved to be correct, then the correctness of the second part becomes mandatory. 

5) Modus tollens

It is a deductive reasoning in which the non-occurrence of one thing or event also eliminates the possibility of the occurrence of another event. 

such as:

• If it is sunny, I will wear sunglasses. 

• It is not sunny. 

so,

• I didn't wear glasses. 

Deductive logic, where the premises are correct and the inferences are correctly applied, gives us 100% certainty of reasoning, it leads to conclusions that are already well known to man, so science is more inductive than deductive logic. Uses logic. 

2) Inductive Logic

In deductive logic we always go to a larger fact based on observations i.e. what is the first premise in deductive logic is the conclusion in deductive logic, deductive logic can never guarantee hundred percent correctness of any proposition. As long as it is true there is nothing in the observation against itAjati

– Types of Inductive Logic

(Tips of Inductive Logic)

There are also many types of deductive logic;

1) Enumerative induction

An example of this would be something like;

• In all the books of medieval philosophers I have read, there is no argument against God. 

• So I have good reason to believe that no medieval philosopher argued against God. 

Now this conclusion is correct, but this conclusion is by no means 100% correct, a book that contains arguments against the existence of God can disprove this argument. This also makes this type of logic weak, which will be discussed later. Well, this problem is called the Problem of Induction in the language of philosophy. That's why in enumerative induction you should have more data, i.e. if you are drawing conclusions about books, you have read more books. 

2) Analogical reasoning

Another type of inductive logic is, for example, a machine in your home breaks down and you fix it, then a few days later another machine in your home with the same function breaks down, so you fix it too. Will try to fix it in the same way you did the first one, actually analogical reasoning ie(Analogical reasoning) is called. 

Like;

• Both cheetah and cat are similar. 

• Cheetah is a good hunter. 

so,

• It is quite possible that a cat is also a good hunter. 

Now most of the people will think that this is what we think, yes, it is exactly like that, but logic teaches you a complete method for this reasoning, which I will not explain right now. 

3) Causal Reasoning

There is another type, which we also call Causal Reasoning, in which we try to understand the cause of something. It also has many principles, but we will take the simplest example. 

Like;

• Biscuits are stolen only when X is present. 

so,

• There is good reason to believe that X is the thief. 

That is, if B is an event and B occurs only when A also occurs, then we can infer that B is caused by A. 

Now this reasoning is done but it may not be completely correct here we are making a logical fallacy by considering correlation as causation. That is why it is important that we have seen A happen many times in order for this behavior to happen to B, and that we also do the rest of the reasoning. 

Like;

When A does not exist, B does not exist, meaning that A is the cause of B. John Stuart Mill has written extensively on causal reasoning, which I will explain in full at some point. 

4) Inductive Prediction

Another type of inductive logic is known as inductive prediction, in which we predict future events based on a pattern noted on the basis of observation. 

such as:

• Ali gets sick when he eats peanuts. 

• Ali ate peanuts. 

so,

• It is quite possible that Ali will be ill again. 

This can also cause problems. Which will be discussed further. 

3) Abductive Logic

In probabilistic logic or abductive logic, we make the most possible explanation for any effect based on the observed facts. The conclusion drawn from this is not necessarily correct, but we take the observation and logical conclusion that best explains anything. 

– Types of Probabilistic Logic

(Tips of Inductive Logic)

There are two types of probabilistic logic;

1) HD (H-D)

2) IBE

1) HD (H-D)

In this we observe an event and then reason about its possible causes, then based on further observations we judge one cause to be more possible and believable than the others. 

Like;

• The ground is wet

• There are clouds in the sky

so,

• It may have rained. 

Now the first premise here is that the ground is wet, there could be many reasons, maybe this water has been dropped by someone or it has rained etc. Then we observed more and we saw that there are a lot of clouds in the sky. From which we preferred the rainy explanation over the rest of the explanations. 

2) IBE

In this, when we see an event, we do not automatically accept its various causes, but we make further observations, and then the explanation that fits all the evidence is accepted. 

Like;

You saw that a pot was broken in the house, when you came from the room where the sound of breaking was heard, the window was broken and there was also a ball in the room, so you guessed that someone had entered your house while playing cricket. hit the ball towards which it broke because that is the explanation for the breaking of the window and the cricket ballThere presence can be understood properly.